1. Field of the Invention
The present invention relates to the field of fingerprinting.
2. Related Art
Fingerprinting is a common method of distinguishing an individual. No two people have identical fingerprints on all ten fingers. Fingerprinting is used for identification in many commercial and legal settings. Law enforcement officials have often used fingerprinting for identification purposes. Conventional techniques for obtaining fingerprint images include application of ink to a person""s fingertips and rolling or pressing the tips onto a recording card. This method has severe limitations. For instance, the ink can be extremely messy, and easily smear or blur, often requiring many attempts before a usable print is obtained. Further, it is difficult to adapt ink prints for computerized storage and retrieval, thus making it difficult for various governmental agencies to reliably transfer and share data.
To address this problem, fingerprint scanners have been developed to capture fingerprint images in digital data form, allowing an image to be saved in a database and allowing the saved image to be easily accessed and retrieved. Fingerprint Examiners and/or Automated Fingerprint Identification Systems can then use the digital images for identification of individuals. However, use of a scanner to capture the print still holds drawbacks. Current scanners require trained personnel to guide the fingers over the optical reading area while maintaining an accurate position and rate of rotation. If the fingers are not rotated at a proper rate, or their position is inaccurate, then data is lost, requiring the procedure to be conducted again. The problem is compounded when the person being fingerprinted is uncooperative, as is sometimes the case in law enforcement. Such methods require training and practice and can be both time consuming and tedious.
Movable platens allow the finger axis to be fairly stationary, while the finger rotates. This reduces the difficulty of rotating a finger at a specific, correct speed, but still requires proper positioning of the finger. The finger must be held in-line with the stationary scanning optics, as current scanners input only a narrow slice of data at a time. Therefore, there is a need for a finger guide, to provide a positioning framework for a finger. The finger guide of the present invention fills this need by providing a positioning reference, preferably used in conjunction with a movable platen. The guide assists when taking roll fingerprints, and may be moved out of the way when taking impressions or flat prints.
The present invention is a scanning device for electronically capturing a fingerprint image, employing a finger guide unit and a platen. The guide unit positions a finger for scanning. A finger is placed in a gap in the guide. The guide maintains the finger within a print scanning range when used in conjunction with a movable platen. This increases the likelihood of capturing a clear, well-defined print in the scanning process. This, in turn, increases efficiency.
The guide unit is rotatable allowing the whole unit to be moved to expose the movable platen. This allows the operator to access the whole platen when desirable, such as when an officer would need to capture a four-finger plain impression or to clean the platen. The guide rotates about a pivot shaft 180 degrees to a resting position. When desired, the guide may be rotated back into position above the platen to aid in further roll fingerprinting.
The finger guide unit of the preferred embodiment has two guide plates disposed adjacent one another creating a gap in which a finger can be placed for scanning. The gap width is adjustable by means of an adjustment device, allowing fingers of any size to be properly positioned and guided within the scanner reading range. The adjustment device changes the gap width by means of an adjustment wheel and threaded screws disposed in threaded apertures in the guide plates. When the adjustment wheel is turned, the screws rotate and move both guide plates equally and simultaneously in opposite directions, allowing the gap centerline to remain undisturbed. The adjustment wheel is held between the guide plates by means of an adjustment mount. The pivot shaft and threaded screws likewise pass through this adjustment mount. The guide plates each have an edge lined with low-friction material which contacts the finger when in use. This allows the finger to be smoothly rotated within the guide, allowing for easy and simple print capturing.
The finger guide plates each have an extension which serves as a handle for raising the guide unit and as a hanger for suspending the guide unit above the platen for use. The guide plates also have an alignment rod disposed between them to ensure stabilization and alignment.
Further embodiments, features and advantages of the present invention, as well as the structure and operation of the various embodiments of the present invention, are described in detail with reference to the accompanying drawings.